A group of immigration detainees involved in recent protests or deemed "high risk" have been moved to Perth's maximum security Casuarina prison.

Six men were transferred from the Yongah Hill centre, 96 kilometres north-east of Perth, to the jail after rooftop protests last month.

They are understood to comprise five asylum seekers and an Egyptian man, with children living in Perth, facing possible deportation after serving prison time for fraud offences.

Three of the asylum seekers are from Iran.

The men are believed to have been assessed as high risk and no longer suitable to be kept at Yongah Hill, which was set up to house low-risk detainees.

Although the men have not been charged, they are being held at Casuarina because the Migration Act allows immigration detention at a state or Commonwealth prison or remand centre.

In a statement, the Department of Immigration and Border Protection said detainees were "expected to behave reasonably and uphold all Australian laws".

"The department will not hesitate to use all available resources at its disposal to maintain safe and secure detention facilities," the statement said.

"This includes legal, court and police resources, the use of more strictly managed accommodation and more stringent controls against disruptive behaviour, and the relocation of disruptive detainees to other facilities as appropriate."

The department added it would not be appropriate to comment on specific detainee transfers.

Two of the men sent to Casuarina are believed to have since been transferred to detention on Christmas Island, where nine other men from Yongah Hill, also involved in protests, were also sent on Saturday.

Meanwhile, ABC Mornings has reported a 25-year-old Iranian asylum seeker on hunger strike was still in Royal Perth Hospital, but was conscious and talking.